From 39457ace2f8048aa82d180040b1bce9ca59a6b74 Mon Sep 17 00:00:00 2001
From: ubkp <118854183+ubkp@users.noreply.github.com>
Date: Mon, 11 Dec 2023 05:11:20 -0300
Subject: [PATCH] [rcore] Add `ToggleBorderlessWindowed()` implementation for
 `PLATFORM_WEB` (#3622)

* Add ToggleBorderlessWindowed() for PLATFORM_WEB

* Fix coding convention
---
 src/platforms/rcore_web.c | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/platforms/rcore_web.c b/src/platforms/rcore_web.c
index ae210853b..c322a1d52 100644
--- a/src/platforms/rcore_web.c
+++ b/src/platforms/rcore_web.c
@@ -211,7 +211,33 @@ void ToggleFullscreen(void)
 // Toggle borderless windowed mode
 void ToggleBorderlessWindowed(void)
 {
-    TRACELOG(LOG_WARNING, "ToggleBorderlessWindowed() not available on target platform");
+    const bool wasFullscreen = EM_ASM_INT( { if (document.fullscreenElement) return 1; }, 0);
+    if (wasFullscreen)
+    {
+        EM_ASM(document.exitFullscreen(););
+
+        CORE.Window.fullscreen = false;
+        CORE.Window.flags &= ~FLAG_FULLSCREEN_MODE;
+    }
+
+    if (!IsWindowState(FLAG_BORDERLESS_WINDOWED_MODE))
+    {
+        // NOTE: 1. The setTimeouts handle the browser mode change delay
+        //       2. The style unset handles the possibility of a width="100%" like on the default shell.html file
+        EM_ASM(
+            setTimeout(function()
+            {
+                Module.requestFullscreen(true, true);
+                setTimeout(function()
+                {
+                    canvas.style.width="unset";
+                }, 100);
+            }, 100);
+        );
+
+        CORE.Window.flags |= FLAG_BORDERLESS_WINDOWED_MODE;
+    }
+    else CORE.Window.flags &= ~FLAG_BORDERLESS_WINDOWED_MODE;
 }
 
 // Set window state: maximized, if resizable